JP4201024B2 - 2-Cyanoacrylate composition and instant adhesive - Google Patents

Description

The present invention relates to a 2-cyanoacrylate composition that changes color in response to curing and an instantaneous adhesive composed of the composition, and since it is colored before curing, it is subjected to adhesion, filling, or surface treatment. Since the part can be easily recognized visually and becomes colorless or weak after curing, the appearance of the part subjected to adhesion, filling or surface treatment is improved, and the moment made of the composition It relates to adhesives.

Since 2-cyanoacrylate instantaneously anionic polymerizes to form a strong polymer, it is widely used as an instant adhesive or a fast-curing filler in various industries, medical fields, leisure fields, and general households. ing.
This cured product of 2-cyanoacrylate is generally colorless and transparent, and has a feature that adhesion, filling, or surface treatment is inconspicuous and does not impair the appearance.
However, since it is colorless and transparent even in the liquid state at the time of application / filling, the place of application / filling is difficult to understand. In addition, it has a drawback in terms of work that it is difficult to determine the coating amount.

In order to solve such problems, various methods have been studied conventionally.
For example, a method of adding a color material into 2-cyanoacrylate (Patent Document 1) and a method of blending an anthraquinone color material with good color developability into 2-cyanoacrylate (Patent Document 2) can be mentioned.
Furthermore, using a coloring material having a structure that emits specific fluorescence, a method of visually recognizing by irradiating with ultraviolet rays (Patent Document 3), or coloring by adding a salt composed of a basic dye and various acids (Patent Document 4).

US Pat. No. 2,784,127 (column 5) US Pat. No. 3,699,076 (column 3-5, column 8) U.S. Pat. No. 4,405,750 (columns 4-5) JP 52-65531 A (claims, page 3)

When adhesion, filling, or surface treatment is performed using a 2-cyanoacrylate-based composition, for applications where workability is a problem, it is colored to a good degree of visibility before curing. Is preferred.
On the other hand, considering the appearance after bonding, it is preferable that the cured product or the protruding portion is not conspicuous, that is, colorless and transparent or nearly colorless.

However, with regard to the blending of the color material, the normal visible color material has a drawback that although the visibility at the time of application is improved, the cured product is also colored, so that the aesthetic appearance is impaired.
In addition, the fluorescent color material exhibits visibility when irradiated with ultraviolet rays, but has some drawbacks such as the necessity of an ultraviolet irradiation device and the adverse effect of ultraviolet rays on the human body.

This invention improves the drawbacks of the prior art as described above, and since it is colored before curing, it has good visibility and excellent workability, and after curing, the appearance of adhesion, filling, or surface portion that becomes colorless or light-colored. It is an object of the present invention to provide a good 2-cyanoacrylate composition that changes color according to curing and an instantaneous adhesive comprising the composition.

  As a result of intensive studies to solve the above problems, the inventors have surprisingly solved the above problems by coloring a specific colorant into 2-cyanoacrylate, and coloring before curing, The present inventors have completed the present invention by finding a 2-cyanoacrylate composition that becomes colorless or light after curing.

According to the first aspect of the present invention,
The main component is 2-cyanoacrylate,
Contains methyl yellow, methyl red or pentamethoxy red as a colorant ,
Does not contain dilution solvent,
2-cyanoacrylate-based composition, characterized in that changes color depending on the curing of the 2-cyanoacrylate.

The invention according to claim 2 of the present invention is
The 2-cyanoacrylate composition according to claim 1,
The color material is
It is characterized by being pentamethoxy red .

Moreover, this invention is the invention according to claim 3,
An instant adhesive comprising the 2-cyanoacrylate composition according to claim 1 .

Since the 2-cyanoacrylate composition of the present invention is colored before curing, the visibility is good and the workability is excellent, and after curing it becomes colorless or light color, the appearance of adhesion, filling or surface treatment site is good. Become.
For this reason, since it is excellent in workability | operativity and the finish is favorable, in the industry and a household, especially the use for which an accuracy is requested | required, application workability | operativity and curability are balanced at a high level.
Furthermore, since the good work becomes possible, the use in each field can be further widened.
In addition, even when used by general consumers with little knowledge of bonding, filling, or surface treatment, it is easy to determine the location and amount of application, and the work can be done without worrying about the effect of the protruding part on the finish. It has a great effect on various industries.

  Hereinafter, the 2-cyanoacrylate composition according to the present invention will be described in detail.

<Color material>
The color material used in the present invention is methyl yellow, methyl red or pentamethoxy red , and particularly preferred for the present invention is pentamethoxy red.
These coloring material, 2-cyanoacrylate be one that turned pale or colorless in parallel with the curing before and after curing, in color transition range, the acidic side, the color visibility good color, and alkaline side is Chi lifting weaker tones more complete colorless or acidic side, by using these coloring materials, before curing of 2-cyanoacrylates is a visible color, color after curing of 2-cyanoacrylate the state, and are not to allow discoloration of low visibility colorless or light-colored, and makes it possible to cure the determination of 2-cyanoacrylate by being blended in the 2-cyanoacrylate-based composition.

The blending amount of the coloring material with respect to the 2-cyanoacrylate-based composition cannot be defined unconditionally because the degree of color development varies depending on the type, but usually 0.5 to 1500 wtppm (hereinafter simply referred to as ppm unless otherwise specified). Is preferable, and more preferably 5 to 500 ppm.
If it is more than this, the curability of the 2-cyanoacrylate composition will be adversely affected, and if it is less than this, the coloration will be too thin and the visibility will deteriorate, which is not preferred.

<2-Cyanoacrylate>
The 2-cyanoacrylate that can improve the workability of the 2-cyanoacrylate composition using the color material of the present invention is a cyanoacrylate derivative used for applications such as adhesion, filling, or surface treatment.

  Specific examples thereof include methyl-2-cyanoacrylate, ethyl-2-cyanoacrylate, propyl-2-cyanoacrylate, isopropyl-2-cyanoacrylate, butyl-2-cyanoacrylate, isobutyl-2-cyanoacrylate, amyl- 2-cyanoacrylate, hexyl-2-cyanoacrylate, cyclohexyl-2-cyanoacrylate, octyl-2-cyanoacrylate, 2-ethylhexyl-2-cyanoacrylate, allyl-2-cyanoacrylate, propargyl-2-cyanoacrylate, phenyl 2-cyanoacrylate, benzyl-2-cyanoacrylate, methoxyethyl-2-cyanoacrylate, ethoxyethyl-2-cyanoacrylate, tetrahydrofurfuryl-2-cyanoacrylate 2-chloroethyl-2-cyanoacrylate, 3-chloropropyl-2-cyanoacrylate, 2-chlorobutyl-2-cyanoacrylate, 2,2,2-trifluoroethyl-2-cyanoacrylate or hexafluoroisopropyl- Examples include 2-cyanoacrylate.

  These 2-cyanoacrylates may be used as a composition for adhesion, filling or surface treatment using only one kind, or a mixture of two or more kinds of 2-cyanoacrylates.

<Other ingredients>
The 2-cyanoacrylate composition of the present invention contains a coloring material and 2-cyanoacrylate as essential components.
When used as an adhesive, an anionic polymerization stabilizer, a radical polymerization stabilizer, a thickener, a curing accelerator, a plasticizer, and a thixotropic agent are added in addition to these as necessary.

As the anionic polymerization stabilizer, conventionally known anionic polymerization stabilizers can be used. Sulfurous acid gas, nitric oxide, hydrogen fluoride, sultone compounds, BF ₃ ether complex, BF ₃ acetic acid complex or BF ₃ methanol complex, methane Examples thereof include sulfonic acid and p-toluenesulfonic acid.
Generally, the preferable addition amount is in the range of 1 wtppm to 1 wt%.
As will be described later, since these have a great influence on the color change performance, it is important to select an appropriate addition amount depending on the color material to be combined.

This anionic polymerization stabilizer is generally an acidic compound.
In addition to this, the 2-cyanoacrylate-based composition contains various acidic compounds such as impurities derived from a depolymerization catalyst and impurities derived from a distillation stabilizer that are mixed during the synthesis process.
The discoloration of the pH indicator as the coloring material used in the present invention is affected by the type and amount of these acidic compounds.
For example, when BF ₃ ether complex, BF ₃ acetic acid complex, BF ₃ methanol complex, or the like is used as an anionic polymerization stabilizer, the pH required for the color material is slightly shifted to the acidic side (that is, the color change region is shifted to the acidic side). There is a tendency to move.
In addition to this, the acidic compound has a great influence on the curing speed and product life as a 2-cyanoacrylate composition, so it is appropriate from various aspects such as target curing performance, product life and discoloration performance. It is important to select an appropriate amount and combination.

A conventionally known radical polymerization stabilizer can be used as the radical polymerization stabilizer.
Specific examples include hydroquinone, hydroquinone monomethyl ether, catechol, pyrogallol and the like, and the preferred addition amount is in the range of 1 wtppm to 1 wt%.

  In order to increase the adhesion rate, polyalkylene oxide and derivatives thereof, crown ether and derivatives thereof, silacrown ether and derivatives thereof, calixarene derivatives, thiacalixarene derivatives, and the like can be added as an anionic polymerization accelerator.

A conventionally well-known thickener can be used as a thickener.
Specific examples include polymethyl methacrylate, methyl methacrylate / acrylic acid ester copolymer, methyl methacrylate / methacrylic acid ester copolymer, and cellulose derivatives.
The preferable addition amount is in the range of 0.1 to 20 wt%.

  A conventionally well-known plasticizer can be used as a plasticizer, An alkyl phthalate, specific polyvalent (meth) acrylate, etc. are mentioned, The preferable addition amount is the range of 0.01-30 wt%.

  As the thixotropic agent, a conventionally known thixotropic agent can be used, and specifically, hydrophobic silica can be used, and a preferable addition amount thereof is in the range of 0.1 to 20 wt%.

In addition to the above, an adhesion imparting agent, a fragrance, a filler, a crosslinking agent, a toughener, a polymerization initiator, an organic solvent, and the like are added depending on the purpose.
Also in these respects, all conventionally known techniques can be introduced into the 2-cyanoacrylate composition of the present invention.

The 2-cyanoacrylate composition of the present invention is colored before curing, but becomes colorless or light after curing.
This change is caused when the pH in the system is, for example, when sulfurous acid gas is used as an anionic polymerization stabilizer, from about pH 2 to 3 before curing and from 3.5 to 4 after curing considering the change of the indicator added. This is because it has changed to about 5.

This change in pH is mainly caused by the fact that the water content is kept at several tens to several hundred ppm or less before curing, but the water content in the system increases to several thousand ppm or more after curing.
In addition to this, as other factors, factors such as a decrease in the anionic polymerization stabilizer during curing and a decrease in acidity such as dissolution of impurities on the surface of the adhesive substrate work.

Due to this change, the acidity in the 2-cyanoacrylate composition, which is usually strongly acidic by the polymerization inhibitor, is slightly reduced.
In this system, when the color material of the present invention in which the color change range is in the range of pH 1 to 4 is blended, even if it has an acid side color of the blended color material before curing, it is alkaline side after curing. Presumed to develop color.

Further, the 2-cyanoacrylate composition after curing is considered to have a pH corresponding to approximately 2.5 to 5, and using these properties, the color change from colored to colorless as described above, Color change from colorless to light is possible.

Hereinafter, although the 2-cyanoacrylate type composition of this invention is demonstrated in detail with an Example and a comparative example, this invention is not limited to these examples.
The evaluation of the 2-cyanoacrylate-based composition was performed mainly for the performance as an adhesive, and was performed by the following method.

(1) Set time measuring method It measured according to JISK6861-1995 using the test piece and composition made from a hard vinyl chloride resin.
(2) Bond strength measurement method (Rigid vinyl chloride resin)
A test piece made of hard vinyl chloride resin having the dimensions used in the tensile shear bond strength test described in JIS K 6661-1995 was used, and the test pieces were laminated with the composition and cured for 24 hours, and then the tensile shear bond strength test was performed.
(3) Appearance (Liquid appearance)
In order to observe the liquid appearance in the coated state, the composition was coated on a white polyacetal resin plate with a thickness of about 0.5 mm, similar to the state where one drop (about 0.02 g) of the composition was coated on the substrate. The appearance was observed.
(Appearance of cured product)
Similar to the liquid appearance in the above-mentioned application state, the composition was applied on a white polyacetal resin plate with a thickness of about 0.5 mm, and the appearance after complete curing after 24 hours at 25 ° C. × 60% RH was observed.

<Example 1>
Pentamethoxy red was mixed with ethyl-2-cyanoacrylate (50 ppm of sulfurous acid gas added) so that the content thereof was 1 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 2>
A 2-cyanoacrylate composition was prepared by mixing pentamethoxy red with the same ethyl-2-cyanoacrylate as in Example 1 so that the content thereof was 10 ppm, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 3>
A 2-cyanoacrylate composition was prepared by mixing pentamethoxy red with the same ethyl-2-cyanoacrylate as in Example 1 so that the content thereof was 100 ppm, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 4>
A 2-cyanoacrylate composition was prepared by mixing pentamethoxy red with the same ethyl-2-cyanoacrylate as in Example 1 so that the content thereof was 1000 ppm, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 5>
Methyl yellow was mixed with the same ethyl-2-cyanoacrylate as in Example 1 so that the content thereof was 10 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 6>
Methyl yellow was mixed with the same ethyl-2-cyanoacrylate as in Example 1 so that the content thereof was 100 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 7>
Methyl yellow was mixed with the same ethyl-2-cyanoacrylate as in Example 1 so that the content thereof was 1000 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 8>
A 2-cyanoacrylate-based composition was prepared by mixing pentamethoxy red with ethyl-2-cyanoacrylate (100 ppm of BF ₃ methanol complex added) so that the content thereof was 100 ppm, and the above-described evaluation was performed. . The results are shown in Table 1.

<Example 9>
Methyl yellow was mixed with the same ethyl-2-cyanoacrylate as in Example 8 so that the content thereof was 100 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 10>
A 2-cyanoacrylate composition was prepared by mixing pentamethoxy red with isopropyl-2-cyanoacrylate (50 ppm of sulfurous acid gas added) so that the content thereof was 100 ppm, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 11>
Methyl yellow was mixed with the same isopropyl-2-cyanoacrylate as in Example 10 so that the content thereof was 100 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 12>
A 2-cyanoacrylate composition was prepared by mixing pentamethoxy red with ethoxyethyl-2-cyanoacrylate (50 ppm of sulfurous acid gas added) so that the content thereof was 100 ppm, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 13>
Methyl yellow was mixed with the same ethoxyethyl-2-cyanoacrylate as in Example 12 so that the content thereof was 100 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 14>
A 2-cyanoacrylate composition is prepared by mixing pentamethoxy red with the same ethyl-2-cyanoacrylate as in Example 8 so that the content is 50 ppm and crown ether O-18 is 500 ppm. Were prepared and evaluated as described above. The results are shown in Table 1.

<Example 15>
The same as in Example 8 so that the content of pentamethoxy red is 50 ppm, the content of crown ether O-18 is 500 ppm, and the content of polymethyl methacrylate (molecular weight is 1 million) is 4 wt%. A 2-cyanoacrylate composition was prepared by mixing with ethyl-2-cyanoacrylate, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 16>
The same ethyl-2 as in Example 8 was used so that the content of pentamethoxy red was 50 ppm, the content of crown ether O-18 was 500 ppm, and the content of dipentaerythritol hexaacrylate was 5 wt%. A 2-cyanoacrylate composition was prepared by mixing with -cyanoacrylate, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 17>
The same ethyl-2-cyanoacrylate as in Example 8 so that the content of pentamethoxy red is 50 ppm, the content of crown ether O-18 is 500 ppm, and the content of dimethyl phthalate is 5 wt%. To prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Example 18>
The same ethyl-2-cyano as in Example 8 so that the content of pentamethoxy red is 50 ppm, the content of crown ether O-18 is 500 ppm, and the content of tributyl acetylcitrate is 5%. A 2-cyanoacrylate composition was prepared by mixing with acrylate, and the above-described evaluation was performed. The results are shown in Table 1.

<Comparative Example 1>
The above-mentioned evaluation was performed on an ethyl-2-cyanoacrylate composition (addition of 50 ppm of sulfurous acid gas) not containing a coloring material. The results are shown in Table 1.

<Comparative example 2>
The above-described evaluation was performed on an ethyl-2-cyanoacrylate composition (added with 100 ppm of BF ₃ methanol complex) in which no colorant was blended. The results are shown in Table 1.

<Comparative Example 3>
The above-mentioned evaluation was performed on an isopropyl-2-cyanoacrylate-based composition (addition of 50 ppm of sulfurous acid gas) not containing a coloring material. The results are shown in Table 1.

<Comparative example 4>
The above-described evaluation was performed on an ethoxyethyl-2-cyanoacrylate composition (addition of 50 ppm of sulfurous acid gas) not containing a coloring material. The results are shown in Table 1.

<Comparative Example 5>
A 2-cyanoacrylate composition was prepared by mixing Macrolex Red (trade name of Bayer) with the same ethyl-2-cyanoacrylate as in Comparative Example 1 so that the content was 100 ppm. Went. The results are shown in Table 1.

<Comparative Example 6>
Macrorex red was mixed with the same ethyl-2-cyanoacrylate as in Comparative Example 2 so that the content thereof was 100 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

<Comparative Example 7>
A 2-cyanoacrylate composition was prepared by mixing Macrolex Red with the same isopropyl-2-cyanoacrylate as in Comparative Example 3 so that the content thereof was 100 ppm, and the above-described evaluation was performed. The results are shown in Table 1.

<Comparative Example 8>
Macrorex red was mixed with the same ethoxyethyl-2-cyanoacrylate as in Comparative Example 4 so that the content thereof was 100 ppm to prepare a 2-cyanoacrylate composition, and the above-described evaluation was performed. The results are shown in Table 1.

As described in each example of Table 1, it can be seen that the 2-cyanoacrylate composition of the present invention has different colors before and after curing.
It can also be seen that by selecting an appropriate blending amount, the same level of curing performance as that without adding a colorant is maintained.

On the other hand, in the comparative example of Table 1, when no color material is added, both before and after curing are colorless and transparent.
In addition, when the coloring material is added, all are colored in the same color, and the discoloration effect as in the present invention is not seen.

Claims (3)

The main component is 2-cyanoacrylate,
Contains methyl yellow, methyl red or pentamethoxy red as a colorant ,
Does not contain dilution solvent,
A 2-cyanoacrylate composition which changes color according to the curing of 2-cyanoacrylate. The color material is
The 2-cyanoacrylate composition according to claim 1, which is pentamethoxy red . An instantaneous adhesive comprising the 2-cyanoacrylate composition according to claim 1 or 2 .